Architecture to Illuminate a Display Panel

ABSTRACT

A system comprising an illumination system to direct light from one or more light sources to a limiting output pupil of a projection optomechanical system, a liquid crystal on silicon display panel (LCOS) to modulate the light from the projection optomechanical system and to direct the modulated light back toward the projection optomechanical system, and an in-coupler to a combiner waveguide to receive the modulated light from the LCOS, after it passes through the projection optomechanical system. The system in one embodiment is designed so that the light that passes through the projection optomechanical system from the illumination system lands on the LCOS within the limiting output pupil of the projection optomechanical system.

RELATED APPLICATION

The present application claims priority to U.S. Provisional PatentApplication No. 63/085,120, filed on Sep. 29, 2020, and incorporatesthat application in its entirety by reference.

FIELD

The present invention relates to an architecture for illuminating adisplay panel utilizing a combiner waveguide.

BACKGROUND

A traditional LCOS (liquid crystal on silicon) system, including theillumination and projection optics, is shown in FIGS. 1A-1C. LCOS is areflective display technology that requires an external source ofpolarized illumination. The light is often provided by separate red,green, and blue LEDs (light emitting diodes). The light from the LEDs,in the prior art configuration, are combined using an X-cube to combinethe light from the three different LEDs, providing the different colors.In some embodiments, a lens is used in front of the LED to focus thelight. The output of the X-cube passes through an MLA (microlens array)which focuses the light to intermediate optics.

A range of filters and optical elements, including condenser lenses,microlens arrays, and relay lenses, shape the light to match thefootprint of the LCOS panel, and give it the necessary angularproperties for the projection optics. This light is reflected onto thesurface of the LCOS panel using a polarizing beam splitter (PBS). Lightthat is modulated by the LCOS panel then passes through the PBS andenters the projection optics. When used with a waveguide (WG) in anaugmented reality (AR) application, the in-coupler of the waveguide isplaced at the exit pupil of the projection optics.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIGS. 1A-1C illustrate prior art configurations of LCOS-based systems.

FIG. 2 illustrates one embodiment of the use of an illumination systemand combiner waveguide.

FIG. 3 illustrates one embodiment of an alternate configuration, inwhich the illumination waveguide contains a corner.

FIG. 4 illustrates one embodiment of the illumination waveguideincluding a curved element.

FIG. 5 illustrates one embodiment of an illumination waveguide in whicha polarizing beam splitter is used to enable shifting of the elements.

FIG. 6 illustrates one embodiment of a configuration in which theprojection optics include a reflective mirror.

FIG. 7A illustrates one embodiment of the dual waveguides where theoutput of the illumination waveguide and input of the combiner waveguideare offset with respect to each other.

FIG. 7B illustrates another embodiment of the dual waveguides that areoffset.

FIG. 8 illustrates another embodiment in which the illuminationwaveguide is positioned behind the combiner waveguide.

FIG. 9 illustrates one embodiment of the waveguides, in which theillumination waveguide fully overlaps the combiner waveguide.

FIG. 10 illustrates one embodiment of the waveguides, in which theillumination waveguide is adjacent to the combiner waveguide.

FIG. 11 illustrates one embodiment of another view of the waveguideswith the out-coupler of the illumination waveguide and the in-coupler ofthe combiner waveguide next to each other.

FIG. 12 illustrates one embodiment of another view of a single piece ofglass or other material, which form both the illumination waveguide andthe combiner waveguide.

FIGS. 13A-13C illustrate different perspectives of one embodiment of asystem in which each color has a separate illumination waveguide.

FIG. 13D illustrates one embodiment of the system in which each colorhas a separate combiner waveguide.

FIGS. 14A-14B illustrate one embodiment of the waveguide system forbinocular display.

FIG. 15 illustrates one embodiment of the waveguides used with asteerable display.

FIG. 16 illustrates another embodiment of the waveguides used with afield display and steerable display.

FIG. 17 illustrates one embodiment of using polarization-selectiveout-coupling and in-coupling to separate the light for the field displayand the steerable display.

FIG. 18A shows a side view of an illumination waveguide including apolarization converter in one embodiment.

FIG. 18B illustrates one embodiment of the polarization converter of theillumination waveguide of FIG. 18A.

FIG. 19 illustrates one embodiment of the system using a light combineras an illumination system.

FIG. 20 illustrates another embodiment of the system using a lightcombiner as an illumination system.

FIG. 21A illustrates one embodiment of a combiner waveguide withseparate lights and in-couplers for each of the colors.

FIG. 21B illustrates one embodiment of color-separated combinerwaveguides.

FIG. 22 is an illustration of one embodiment of smart glasses in whichthe waveguide display may be used.

FIGS. 23A-23C illustrate one embodiment of a dual hinge system for thesmart glasses.

FIGS. 24A-24C illustrate one embodiment of an arm with a cut-out.

FIG. 24D illustrates another embodiment of an arm with a cut-out.

FIGS. 24E-24F illustrate one embodiment of an arm with a cut-out thathas an inside hinge.

FIGS. 25A-25C illustrate another embodiment of the arm to protect thelight engine.

FIGS. 26A and 26B illustrate embodiments of the hinging element.

FIGS. 26C and 26D illustrate the open and closed configurations of anarm with an outside hinge.

FIGS. 27A-27C illustrate one embodiment of a rotating hinge, in whichthe arm is rotated to open or close.

FIG. 28 illustrates one embodiment of a dual hinge.

FIGS. 29A-29D illustrate one embodiment of glasses with a front rotatingarm, in which the closed position has the arms in front of the lenses.

FIGS. 30A-30B illustrate one embodiment of an over-engine hinge.

FIG. 31 illustrates one embodiment of glasses with a foldable bridge.

DETAILED DESCRIPTION

The present application in one embodiment reduces the volume oftraditional illumination optics by aligning the output of theillumination system to the exit pupil of the projection optics. In thiscontext, alignment means that the illumination pupil and the imagingpupil fall within the exit pupil of the projection optics. However, theydo not have to be aligned along the optical axis. In one embodiment, thedesign utilizes a set of optics through which the light travels twice,once from the illumination source to an LCOS panel, and once returningfrom the LCOS panel to the in-coupler of a combiner waveguide. In oneembodiment, the design also replaces many of the elements of thetraditional illumination optics with an illumination combining element,such as illumination waveguide or illumination prism, X-cube combiner,or other combining element, with its output aligned to the exit pupil ofthe projection optics, and uses the same optics for illumination andprojection. In one embodiment, the present system may be integrated intoa head-mounted device (HMD) such as glasses to display visual content toa user. In one embodiment, such glasses may be implemented with ahinging system that enables the display configuration shown in a glassesconfiguration which has a hinging mechanism that functions like atraditional glasses hinge, while providing structure for the lightengine.

The following detailed description of embodiments of the invention makesreference to the accompanying drawings in which like references indicatesimilar elements, showing by way of illustration specific embodiments ofpracticing the invention. Description of these embodiments is insufficient detail to enable those skilled in the art to practice theinvention. One skilled in the art understands that other embodiments maybe utilized and that logical, mechanical, electrical, functional, andother changes may be made without departing from the scope of thepresent invention. The following detailed description is, therefore, notto be taken in a limiting sense, and the scope of the present inventionis defined only by the appended claims.

FIG. 2 illustrates one embodiment of the system 200. The illustrateddesign shows the light sources and waveguides for one eye. In oneembodiment, an identical configuration is used for the other eye in apair of glasses or goggles to display virtual reality, augmentedreality, or mixed reality content to a user. In one embodiment, thelight engine 205 outputs the image for display 250 to the combinerwaveguide 270, which outcouples the image for viewing to a user viaout-coupler 280. The out-coupler 280 may be incorporated into a lens ofsmart glasses, goggles, or similar viewing apparatus.

The illumination system 225 includes an illumination source 210 andillumination light combiner 230. In one embodiment the illuminationsource 210 consists of separate red, green, and blue LEDs 215A, 215B,215C, each with a separate collimating optic 220A, 220B, 220C. In oneembodiment, the three LEDs can be incorporated into a single package,and utilize a single set of collimating optics. In one embodiment, thesecollimating optics 220 include a compound parabolic concentrator (CPC),which may have a variety of shapes, including square, rectangular,hexagonal, and round. In one embodiment, the illumination system iscatadioptric. In one embodiment, the collimating optics 220 includerefractive optics. In one embodiment, the collimating optics 220 includediffractive optics. In one embodiment, the collimating optics 220include a combination of a CPC and refractive or diffractive optics. Inone embodiment, the illumination source 210 is a microLED array. In oneembodiment, the illumination source 210 is one or more lasers.

The light from the illumination source 210 is in-coupled into anillumination waveguide 230. The illumination waveguide 230 can also bereferred to as the illumination system, and may be replaced by a prism,X-cube, or other type of illumination light combiner. In someembodiments, as shown below, the illumination waveguide 230 may bereplaced with a light combiner and collimation optics. In anotherembodiment, the illumination system may be replaced by a portion of thecombiner waveguide, through which the light passes, as is describedbelow. While the illumination waveguide 230 is illustrated as a shortwaveguide, its length may be adjustable to move the light from the lightsource 210 to a combiner.

The in-couplers 235 may be dichroic filters, in one embodiment. Inanother embodiment, the in-couplers 235 are diffractive gratings. In oneembodiment, the in-couplers 235 are volume holograms. In one embodimentthe in-coupler 235 is a mirror and the colors from the illuminationsource 210 are combined prior to coupling into the illuminationwaveguide 230. Other types of in-couplers 235 may be used.

The out-coupler 240 of the illumination waveguide 230 is located infront of the combiner waveguide in-coupler 275, and directs light towardan optomechanical system 290. The optomechanical system 290, in oneembodiment, includes projection optics 255 and LCOS panel 250. In oneembodiment, the out-coupler 240 is sized to match the area of the exitpupil of the projector, and the angle of the out-coupled light matchesthe field of view of the projection optics 255. In one embodiment, theout-coupler 240 is one or more polarizing beam splitters. In oneembodiment, the out-coupler 240 beam splitter is made with dielectricfilms. In one embodiment, the out-coupler 240 beam splitter is made witha wire grid polarizer. In one embodiment, the out-coupler 240 is one ormore partially reflective elements. In one embodiment, the out-coupler240 is a diffractive element. In one embodiment, the diffractive elementis a surface relief grating. In one embodiment, the diffractive elementis a volume hologram. Other types of out-couplers 240 may be used.

After exiting the illumination waveguide 230, the light goes through theprojection optics 255 to the surface of the LCOS panel 250. Theprojection optics 255 comprise one or more lenses and other opticalelements. While the projection optics are shown linearly aligned withLCOS 250, in a real configuration the light output by the out-coupler240 may be redirected at any angle.

In one embodiment, when the illumination waveguide 230 does not use apolarization selective out-coupler 240, a polarization filter 260 orbeam splitter is included in the projection optics. The polarizationfilter 260 may also be used when the incoming light from theillumination waveguide is polarized, as a clean-up filter. Thepolarization filter 260 may be positioned anywhere between theillumination waveguide and the LCOS panel if the incoming light is notpolarized. In one embodiment, if the light from the illuminationwaveguide 230 is polarized, the polarization filter may be anywherebetween the illumination waveguide and the LCOS panel or the LCOS paneland the in-coupler of the combiner waveguide. The LCOS panel 250modulates the polarization of the light and reflects it back through theprojection optics 255. A portion of the modulated light passes throughthe illumination waveguide out-coupler 240 and into the in-coupler 275of a combiner waveguide 270 (CWG).

In one embodiment, all of the illumination light that exits theillumination waveguide 230 and lands on the LCOS panel 250 also fallswithin the volume of the light that would form the limiting output pupilof the projection optics. The “limiting output pupil of the projectionoptics” is defined as the hypothetical exit pupil formed by theprojection optomechanical system 290 in the case where the display isilluminated at the maximum f/# supported by the projection optics. Here,the optomechanical system 290 means the optical elements as well as anymechanical components in the design that would limit the optical path.In one embodiment, additional light exits the illumination systemoutside the limiting output pupil, but this portion of the light doesnot reach the LCOS panel 250.

In one embodiment, the light that exits the illumination system andlands on the LCOS panel 250 transits through all of the elements of theprojection optics 255.

There are a number of different arrangements of the illuminationwaveguide (IWG) that are possible. In one embodiment, the IWG 230 isbetween the CWG 270 and projection optics 255, and the IWG 230 isstraight, as illustrated in FIG. 2.

In one embodiment, the limiting aperture of the illumination system andthe imaging pupil are both within the limiting output pupil of theprojection optics, but they are not co-planar along the optical axis ofthe system (i.e., they have different distances along the direction ofthe optical axis from the projection optics). In another embodiment, theillumination pupil and the imaging pupil are co-planar along the opticalaxis of the system.

In one embodiment, the system may add optical power on the out-couplerof the illumination waveguide 230. The optical power may be polarizationspecific. In one embodiment, this means that the optical power isapplied only to the out-coupled light, and not to the light that passesthrough the illumination waveguide out-coupler 240, to the in-coupler275 of the combiner waveguide 270.

FIG. 3 illustrates one embodiment of an alternate configuration, inwhich the illumination system contains a corner. In one embodiment theillumination system includes LEDs 310, collimation optics 315,illumination waveguide 330, and turning coupler 335. IWG 330 uses aturning coupler 335 to steer the light from LEDs 310 around a corner. Inone embodiment, the turning coupler 335 is a surface relief grating. Inone embodiment, the turning coupler 335 is a mirror. In one embodiment,the turning coupler 335 is a reflective element.

In this embodiment, the illumination waveguide 330 includes two parts,the input portion 320, and the output portion 325. The input portion 320includes the in-coupler, while the output portion 325 includes theout-coupler 340. Although the two pieces are illustrated at rightangles, the configuration may have the input portion 320 of theillumination waveguide 330 at a variety of angles compared to the outputportion 325, including out of plane. In one embodiment, the inputportion of the waveguide 320 may be at any angle which can be turnedusing turning coupler 335. The input portion 320 of the waveguide 330may extend along all three dimensions, including the Z-axis (protrudingfrom the paper). The light out-coupled by the out-coupler 340 of the IWG330 goes through projection optics 355, to LCOS 350. The modulated lightreturned by LCOS 350 passes again through projection optics 355, to thein-coupler 375 of the combiner waveguide 370.

In another embodiment, the illumination waveguide includes a curvingelement. FIG. 4 illustrates one embodiment of the illumination waveguideincluding a curved element. The light from the light sources 410 issteered by curving the illumination waveguide 430. The curved portion422 of the waveguide may be flexible, or may be rigid. In oneembodiment, in this configuration the illumination waveguide 430 hasthree portions, the input portion 420, the output portion 425, andbetween them a curved portion 422. In one embodiment, the curved portion422 of the illumination waveguide 430 is a fiber optic cable. In oneembodiment, the curved portion 422 of the illumination waveguide 430 isa fiber optic bundle. In another embodiment, the curved portion 422 ofthe illumination waveguide 430 is a light guide. While the illustrationshows the curved portion 422 being in a plane with the input portion 420and the output portion 425 of the illumination waveguide 430, thevarious elements may not be in a plane, but rather may be angled in anyway. The advantage of using an illumination waveguide with a curvedportion 422 is that the relative positioning of the input portion 420and output portion 425 of the illumination waveguide 430 can have anyrelationship, and can be at any distance. The remaining elements,projection optics 455, LCOS 450, combiner waveguide 470, with in-coupler475 and out-coupler 480 in one embodiment operate similarly as theconfiguration described previously.

FIG. 5 illustrates one embodiment of an illumination waveguide in whicha polarizing beam splitter is used to enable shifting of the elements.In one embodiment, the polarizing beam splitter 560 is positionedbetween the out-coupler 540 of the illumination waveguide 530 and theprojection optics 555 as shown in FIG. 5. This enables the reorientationof the projection optics 555 and alternate positioning of the lightsource including LEDs 510 and collimation optics 515. Otherconfigurations may be used. The illumination and optics module 505 couldbe rotated to any angle around the central axis 509 of the in-coupler ofthe combiner waveguide 570. The illumination waveguide 530 could berotated around the central optical axis 508 of the imaging system 507.The in-coupler 575 of the combiner waveguide 570 is matched in size andorientation to the optics.

FIG. 6 illustrates one embodiment of a configuration in which theprojection optics include a reflective mirror. In such an embodiment, apair of reflective mirrors 665 may be used to direct the light from theillumination waveguide 630 to the LCOS panel 650. In one embodiment, thelight from LEDs 610 is polarized. In another embodiment, the light ispolarized before entering the illumination waveguide 630 by polarizingfilter 617, so that all light exiting the illumination waveguide has auniform polarization. In another embodiment, the illumination waveguide630 may include a polarization converter, described in more detailbelow.

In this configuration, the light from the out-coupler 640 of theillumination waveguide 630 passes through a polarizing beam splitter655, then through quarter wave plate 660, and is bounced back by thefirst mirror 665. Because of the quarter wave plate 660, thepolarization is rotated, and the polarizing beam splitter 655 reflectsthe light to the LCOS 650. The LCOS modulated light is then passedthrough the polarizing beam splitter 655, and passes through the secondquarter wave plate 660. It is reflected by the second mirror 665, andwith its rotated polarization, reflected by the polarizing beam splitter655 to the in-coupler 675 of the combiner waveguide 670. In oneembodiment, there is linear polarizer 690 in front of the in-coupler 675of the combiner waveguide 670. Thus, the projection optics 652 in thisembodiment include two mirrors 665, two quarter wave plates 660, and apolarizing beam splitter 655. The curvature of the mirrors applies anoptical power, in one embodiment.

FIG. 7A illustrates one embodiment of the dual waveguides where theoutput of the illumination waveguide 730, and input of the combinerwaveguide 770 are offset with respect to each other. In this case, theilluminating light from the illumination waveguide 730 is offsetspatially from the light returning from the LCOS 750 through theprojection optics 755. This arrangement allows for additionalconfiguration options.

In one embodiment, the illumination waveguide 730 is positioned betweenthe combiner waveguide 770 and the projection optics 755. Note that theillustration shows the light waves in two positions, but of course reallight would extend over the entire area. Although the offset between theillumination waveguide out-coupler 740 and the combiner waveguidein-coupler 775 is shown as being to the right, one of skill in the artwould understand that the offset may be along any dimension, and in anydirection. In one embodiment, the in-coupler 775 and out-coupler 740 arenot in the same plane.

FIG. 7B illustrates a modified version of the dual waveguides. In thisembodiment, the illumination waveguide 730 does not extend past the IWGout-coupler 740. Additionally, the system includes an out-boundpolarizer 764 that the light passes through from the out-coupler 740 ofthe illumination waveguide 730, and a separate in-bound polarizer 762that the light passes through when it is returning from LCOS 750, priorto entering the in-coupler 775 of the combiner waveguide 770. In oneembodiment, the out-bound polarizer 764 and in-bound polarizer 762 areco-planar. In another embodiment, the in-bound and out-bound polarizersare not co-planar. In one embodiment, the in-bound and out-boundpolarizers are linear polarizers with their fast axes orthogonal to oneanother.

FIG. 8 illustrates another embodiment in which the illuminationwaveguide is positioned behind the combiner waveguide. The light travelsin a similar pattern as the light in FIGS. 7A and 7B, with the lightfrom the illumination waveguide 830 out-coupler 840 traveling throughthe combiner waveguide 870, prior to hitting projection optics 855. Thereturning light from LCOS 850 does not travel through the illuminationwaveguide 830, but rather enters directly into the in-coupler 875 of thecombiner waveguide 870. In one embodiment, the polarization filter 860may be replaced by separate in-bound and out-bound polarization filters,as illustrated in FIG. 7B.

FIG. 9 illustrates one embodiment of the waveguides, in which theillumination waveguide fully overlaps the combiner waveguide. In oneembodiment the illumination waveguide 930 is positioned behind thecombiner waveguide 970, and the light 920 from collimation optics 915passes through the combiner waveguide 970, prior to entering theillumination waveguide 930, through in-coupler 935 as in FIG. 9.

FIG. 10 illustrates one embodiment of the waveguides, in which theillumination waveguide is adjacent to the combiner waveguide. In oneembodiment, the out-coupler 1040 of the illumination waveguide 1030 isdirectly adjacent to the in-coupler 1075 of the combiner waveguide 1070.In one embodiment, the combiner waveguide 1070 and the illuminationwaveguide 1030 may be made from a single piece. In one embodiment, theout-coupler 1040 of the illumination waveguide 1030 is separated fromthe in-coupler 1075 of the combiner waveguide 1070 via an opticalbounding element 1045. The optical bounding element 1045 keeps lightfrom crossing between the two waveguides 1030, 1070. In one embodiment,the optical bounding element 1045 is non-reflective. In one embodiment,optical bounding element 1045 may be a layer of light absorbing paint orink, metal, thin film black carbon, polarizer material, carbon, oranother visible light absorbing layer may be used. In one embodiment,optical bounding 1045 is reflective on the IWG side of the element.

FIG. 11 illustrates one embodiment of another view of the waveguideswith the out-coupler of the illumination waveguide and the in-coupler ofthe combiner waveguide next to each other. In one embodiment, theillumination waveguide 1110 has in-couplers 1115 for each of the LEDs.In another embodiment, the in-couplers may be a single in-coupler, asshown above.

The out-coupler 1120 of the illumination waveguide 1110 out-couples thelight toward an LCOS (not shown) which would be extending out of thedrawing, if illustrated. The modulated light from the LCOS is reflectedinto the combiner waveguide 1140 in-coupler 1150. In one embodiment, anexpansion grating 1160 is used, and the light is directed to thecombiner waveguide 1140 out-coupler 1170.

FIG. 12 illustrates one embodiment of another view of a single piece ofglass or other material, which form both the illumination waveguide andthe combiner waveguide. In this configuration, the waveguides may be onthe same piece of glass. In one embodiment, illumination waveguide 1210is positioned parallel to the combiner waveguide 1240. The illuminationwaveguide out-coupler 1220 out couples the light to the LCOS (not shown)which extends from the plane of the waveguide. The light returning fromthe LCOS is in-coupled into the combiner waveguide 1240 through combinerwaveguide in-coupler 1250. In one embodiment, an expansion grating 1260directs the light to combiner waveguide out-coupler 1270.

FIGS. 13A-13C illustrate different perspectives of one embodiment of asystem in which each color has a separate illumination waveguide. FIG.13A shows another view, showing the illumination waveguides 1310, 1320,1330, each having an out-coupler 1315, 1325, 1335, arranged in apattern. The combiner waveguide 1340 has separate in-couplers 1350,1355, 1360 for each of the colors/illumination waveguides. In oneembodiment, the arrangement of the out-couplers 1315, 1325, 1335 andcombiner waveguide in-couplers 1350, 1355, 1360 is in a circle, withcorresponding in-couplers and out-couplers aligned. The lightout-coupled by illumination waveguides out-couplers 1315, 1325, 1335 isreflected by the LCOS (not shown), and then in-coupled into the combinerwaveguide in-couplers 1350, 1355, 1360. In one embodiment, the expansiongrating 1390 expands the light, before they are output by the combinerwaveguide out-coupler 1395.

FIG. 13B illustrates a side view, showing only one of the threeillumination waveguides 1310, with an associated light source 1370 andcollimating optic 1375. As can be seen in this figure, the light fromthe LED 1370 passes through collimating optic 1375, and enters theillumination waveguide 1310 through in-coupler 1305. The out-coupler1315 of the illumination waveguide out-couples the light toward LCOS1380, through optics 1385. The light, modulated by LCOS 1380, passesthrough intermediate optics 1385, and to the in-coupler 1350 of thecombiner waveguide 1340. In one embodiment, the separate illuminationwaveguides 1310, 1320, 1330 may be at different Z-depths.

In one embodiment, there may be separate combiner waveguides for eachcolor. In one embodiment, the CWG in-couplers 1350, 1355, 1360 may be atdifferent Z-depths.

FIG. 13C shows a different perspective, showing the three separate lightsources, each with their corresponding collimation optic, andillumination waveguides. Although it appears in this figure that theLEDs are in line with the intermediate optics 1385, actually, the LEDswould be removed in the Z-axis (into or out of the paper).

FIG. 13D shows an alternative embodiment in which there are separatecombiner waveguides 1396 for each of the colors. In one embodiment, thecombiner waveguides 1396 are stacked on each other, with the CWGin-couplers 1350, 1355, 1360 displaced from each other in a patterncorresponding to the displacement of the illumination waveguides'displacement. Although they are shown in the drawing as overlapping, theCWG in-couplers 1350, 1355, 1360 are displaced from each other.

FIGS. 14A-14B illustrate one embodiment of the waveguide system forbinocular display. Although, in general, all of the designs are intendedfor binocular use, in the embodiment shown in FIGS. 14A-14B, thebinocular design utilizes a single illumination waveguide 1410. In thisembodiment, the illumination waveguide 1410 includes light sources 1420,and the light in one embodiment enters the illumination waveguide 1410through collimation optics 1425. The illumination waveguide 1410includes two out-couplers 1430, 1435, with light having a firstpolarization out coupled through a first out-coupler 1435, and lighthaving a second polarization out-coupled through a second out-coupler1430.

Each out coupler 1430, 1435 has associated intermediate optics 1440,1445 and LCOS 1450, 1455. In one embodiment, an optional polarizationfilter 1447, 1442 may be positioned between the optics 1440, 1445 andLCOS 1450, 1455 or between the out-coupler 1430, 1435 and the optics1440, 1445 or between out-coupler 1430, 1435 and in-coupler 1465, 1475.The light returning from the LCOS 1450, 1455, is directed back throughoptics 1440, 1445 into the appropriate one of the combiner waveguides1460, 1470 through respective in-couplers 1465, 1475. FIG. 14B isanother view of one embodiment of the binocular display shown in FIG.14A. Although as illustrated the illumination waveguide 1410 appears tooverlap the right expansion grating 1490, the two are displaced alongthe Z axis, so the illumination waveguide is above or below the combinerwaveguides 1460, 1470.

FIG. 15 illustrates one embodiment of the waveguides used with a movabledisplay. A moveable display utilizes a steering element to position animage for the user within a viewing area. In one embodiment, thesteerable display is displayed in combination with a fixed display, alsoreferred to as a field display. In one embodiment the steering elementis a mirror. The positioning, in some embodiments, may be to place thehigh resolution steerable image centered to the user's fovea. In oneembodiment, the moveable display includes two display portions, asteerable display, with a first resolution, and a non-steerable or fielddisplay with a second, lower, resolution but with a larger field ofview. In one embodiment, the system utilizes the steerable display andfield display of U.S. Pat. No. 10,514,546, entitled “SteerableHigh-Resolution Display”, and incorporated herein by reference in itsentirety.

The illumination waveguide 1510 receives the light from the lightsources 1514, through in-coupler 1515. The out-coupler 1520 of theillumination waveguide 1510 directs the light through a first set ofoptics 1525. In one embodiment, the out-coupler 1520 of the illuminationwaveguide 1510 is not polarization selective, because light of bothpolarizations are used in this design. A polarizing beam splitter (PBS)1530 splits the light, so that light with a first polarization continuesto the field display LCOS 1540, and light with a second polarization isreflected to steerable optics 1560. The light from the field displayLCOS 1540 is directed back from the field display LCOS 1540 through thePBS 1530 to the in-coupler 1555 of the combiner waveguide 1550.

The light that was reflected by PBS 1530 to steerable optics 1560 isdirected to steering element 1570. Steering element 1570 positions thelight for the image portion to the appropriate location for output, andpasses it through final optics 1580 to steerable display LCOS 1585. Thelight returned from the steerable display LCOS 1585 is again reflectedby the steering element 1570, passes through steerable optics 1560, andis reflected by PBS 1530 through the first set of optics 1525, beforeentering the in-coupler 1555 of the combiner waveguide 1550. In thisway, the combiner waveguide 1550 receives both the field image and asteerable image, for output to the user. Because the light is reflectedby the steering mirror 1570 twice, the position of the steering mirror1570 takes into account the two changes in position, so that the finalposition reflects the selected destination for the moveable image.

In one embodiment, instead of having a combined image including both afield display and a steerable display, the system may include only asteerable display. In such a configuration, PBS 1530, steering optics1560, and field display LCOS 1540 may be removed. Thus, in thisconfiguration, the image from IWG out-coupler 1520 passes through afirst set of optics to the steering element, to a steerable display LCOS1585, and returns. In some embodiments, another one of the optics 1525,1580 may also be removed. In one embodiment, in such a configuration apolarization filter may be placed before or after the first set ofoptics 1525.

FIG. 16 illustrates another embodiment of the field display andsteerable display. In this configuration, the light is reflected fromsteering element 1670 only once. The light from the out-coupler 1620 ofthe illumination waveguide 1610 passes through a first set of optics1625, and is split by PBS 1630 toward field display LCOS 1640 orsteerable display LCOS 1685.

The light split toward the steerable display LOCS 1685 passes throughsteering optics 1660. The light from the steering optics 1660 isreflected by PBS 1665 to fixed mirror 1695, passing twice throughquarter wave plate 1690. It then passes through PBS 1665 to steerabledisplay LCOS 1685. The light from steerable display LCOS 1685 isreflected by PBS 1665, through quarter wave plate 1675, and is reflectedby steering element 1670. Because it passes through the quarter waveplate 1675 twice, the light is then passed through PBS 1665 back tosteering optics 1660, and from there via the PBS 1630 and the first setof optics 1625 to the in-coupler 1655 of the combiner waveguide 1650. Inthis configuration, if the system includes only the steerable displayportion, the first PBS 1630, field display LCOS 1640, and steeringoptics 1660 may be removed. In one embodiment, in such a configuration apolarization filter may be placed before or after the first set ofoptics 1625.

FIG. 17 illustrates one embodiment of using polarization-selectiveout-coupling and in-coupling to separate the light for the field imageand the steerable image with separate out-coupler. The illuminationwaveguide 1710 includes two out-couplers 1720, 1745, one for eachpolarization state. The first polarization state is output through thefirst out-coupler 1720, passes through field display optics 1725, and isreflected from field display LCOS 1730, to the field display in-coupler1735 of the combiner waveguide 1740.

The light with the second polarization state is output through thesecond illumination waveguide out-coupler 1745. The light, in oneembodiment, then passes through first steerable display optics 1750, andsecond steerable display optics 1755, and is reflected from steeringelement 1760, to LCOS 1770. This embodiment shows the steering element1760 paired with a fixed mirror 1795 and two quarter-wave-plates 1790,1775 with a PBS 1765. The other configuration for the steering mirroruse, shown in FIG. 15, may also be used here. In one embodiment, apolarization filter 1742 is positioned before the steerable displayin-coupler 1797, to remove stray light. The light passes throughpolarization filter 1742 after it is modulated by LCOS 1770, before itenters the combiner waveguide 1740.

FIG. 18A shows a side view of an illumination waveguide including apolarization converter in one embodiment. The illumination waveguide1810 has in-couplers, for the light from LEDs 1805. The light travelingalong the illumination waveguide 1810 passes through polarizationconverter 1820, prior to reaching out-coupler 1830. The out-coupler 1830guides the light through optics 1835, and optionally polarization filter1840, to LCOS 1845. The modulated light from LCOS 1845 passes throughpolarization filter 1840, optics 1835, to the combiner waveguide 1815'sin-coupler. The use of polarization converter 1820 ensures that all ofthe light in the waveguide has the same polarization state.

FIG. 18B illustrates one embodiment of the polarization converter 1820of the FIG. 18A. The polarization converter 1820 includes a polarizingbeam splitter 1850 across the waveguide 1810. The portion of the lightthat is in polarization state 1 passes through the PBS 1850. The portionthat is in polarization state 2 is reflected to mirror 1860, or a secondPBS. Mirror 1860 reflects the light, which passes through a half-waveplate 1870. The half-wave plate alters the polarization of the light, sothe light in the waveguide is all of polarization state 1. In this way,all of the light in the illumination waveguide 1810, after thepolarization converter 1820, is polarization state 1.

This requires an illumination waveguide having two thicknesses. Thistype of polarization recapture may be utilized in any of the designsabove which do not use light separation based on polarization states.

FIG. 19 illustrates one embodiment of the system with non-waveguideillumination system. The light from LEDs 1910 passes through collimationoptics 1930, and is combined by light combiner 1920. In one embodiment,illumination light combiner 1920 is an X-cube prism, or illuminationprism. Other types of illumination light combiners may be used. Theoutput of the light combiner 1920 goes through a second part ofcollimation optics 1930, in one embodiment. The LEDs 1910, illuminationlight combiner 1920 and collimation optics 1930 together are theillumination system 1935.

The output of the second part of the collimation optics 1930, in oneembodiment, passes through combiner waveguide 1960. It then passesthrough projection optics 1940, and optionally polarization filter 1945,to LCOS 1950. The light modulated by LCOS 1950 passes back throughprojection optics 1940, and enters the combiner waveguide in-coupler1965. As can be seen, in this embodiment, the light passes through theprojection optics 1940 from the illumination system 1935 to the LCOS1950, and from the LCOS 1950 to the combiner waveguide in-coupler 1965.

FIG. 20 illustrates another embodiment of the system with non-waveguideillumination system. The illumination system 2025 include collimationoptics 2030 and a light combiner 2020. The output of the illuminationsystem 2025 is reflected by a PBS 2035, and passes through projectionoptics 2040. The light passes through an optional polarization filter2045, before impacting LCOS 2050. The light modulated by LCOS 2050passes through optics 2040, and through PBS 2035 before entering thecombiner waveguide 2060 in-coupler 2065.

FIG. 21A illustrates one embodiment of a combiner waveguide withseparate lights and in-couplers for each of the colors. The LEDs 2110pass through the combiner waveguide 2150, through optics 2120, optionalpolarization filter 2125, to LCOS 2130. The modulated light from LCOS2130 passes through optics 2120, before entering the combiner waveguidein-couplers 2140. In one embodiment, the LEDs 2110 are color separated,and matched to their respective in-coupler 2140 for each of the colors.The combiner waveguide 2150 guides the light through, and outputs itthrough combiner waveguide out-coupler 2160. The other view shownillustrates one embodiment of the configuration of the lights andin-couplers. Of course, other arrangements may be used, as long as thesystem enables the light from each LED to be in-coupled to theappropriate in-coupler, after passing through optics 2120 twice, andbeing modulated by LCOS 2130.

FIG. 21B illustrates one embodiment of color separated combinerwaveguides. The LED light sources 2110 pass through the color separatedcombiner waveguides 2170, to optics 2120, to be modulated by LCOS 2130.The polarization filters 2125 may be positioned between the waveguides2170 and the optics 2120, or between optics 2120 and LCOS 2130. Theillustration shows the combiner waveguide in-couplers 2175 displacedalong the X-axis, but as shown in FIG. 21A, the displacement maybe alongtwo axes. The combiner wave out-couplers 2180 in one embodiment areoverlapping, and output the different colors.

In general, the variations between the various embodiments of the exitpupil illumination systems shown may be carried through to otherconfigurations. For example, the illumination system may be theillumination waveguide or the collimation optics and light combiner inany of the waveguides. The optical power applied to the illuminationwaveguide out-coupler may be applied to any configuration which includesan illumination waveguide. The illumination pupil and projection pupilmay be offset or overlapping in any of the configurations. A flexibleportion of the illumination light guide or a turning coupler may be usedfor any other configuration as well. Thus, the configurationsillustrated are not intended to be exclusive, but rather inclusive ofthe various ways in which the illumination light to the LCOS panel andthe modulated light from the LCOS panel both pass through a sharedsubset of the optics.

Thus, the present system provides a design in which light passes throughthe optics from the illumination system to the LCOS, as well as from theLCOS to the in-coupler of a combiner waveguide. Thus, the optics serve adual purpose. Additionally, in one embodiment, the light that exits theoptics and lands on the LCOS also falls within the volume of the lightthat would form the limiting output pupil of the optics on theillumination pass. This design may be used to provide a mechanism forsmart glasses, by using the combiner waveguide as part of the lens ofthe glasses to show content to the user. However, the relationship ofthe LEDs, optics, and LCOS elements need to remain unchanged. Therefore,the smart glasses designs shown below provide a mechanism to enable thelight engine to remain in position which provides the wearable comfortof standard glasses, as well as the ability to close the arms of theglasses for storage.

FIG. 22 is an illustration of one embodiment of smart glasses in whichthe waveguide display may be used. This configuration attaches the hinge2240 at the end of the fixed position light engine 2220. The fixedposition light engine 2220 includes the elements described above, e.g.,the light source, the optics, and the LCOS elements, while the lens ofthe glasses 2210 include the waveguide 2230 to display images to theuser. By providing a fixed position light engine 2220, the presentdesign ensures that the relationship of the elements is not altered overtime, by the arms 2250 moving. Furthermore, the elements in oneembodiment are protected from damage. In one embodiment, the fixedposition light engine 2220 is enclosed in a solid plastic casing, toprotect it and maintain the relationship between the elements. Thewaveguide 2230 in one embodiment is see-through enabling the system tobe used for augmented reality or mixed reality glasses.

FIGS. 23A-23C illustrate one embodiment of a dual hinge system for thesmart glasses. The system includes the frame 2320, and an arm 2330. Thearm is attached in two locations, via a dual hinge arrangement. Theattachment at the side of the glasses frame provides a flexing hinge2350 which provides the comfort and adjustability for wear. The foldinghinge 2340 attached at the bottom of the light engine 2360 provides theability to fold the arms closed for storage.

FIGS. 24A-24C illustrate one embodiment of an arm with a cut-out. Theconfiguration shown provides a single hinge, attached to the top of thelens rims. The hinge 2440 is positioned on the top and bottom of thefixed light engine 2460, and enables the arm 2430 to fold using acut-out. The cut-out 2435 enables the light engine 2460 to pass throughthe arm 2430 when the arm is folded. In one embodiment, the arm may alsoinclude a cable routing 2470 along which a wire may be lead. This wiremay be used to attach other elements of the system, or provide power,for example.

FIGS. 24D-24F illustrate another embodiment of an arm 2492 with acut-out. In this configuration, the frame attachment point 2480 is tothe lens rim above the fixed light engine 2460. The arm has a lightengine protector 2490 which protects the light engine, when the arm isin the open position. When the arm is in the closed position, the lightengine 2460 goes through the cut-out in the arm. This can be furtherseen with the arm shown in the open position in FIG. 24F and the closedposition in FIG. 24E.

FIG. 25A illustrates another embodiment of the arm to protect the lightengine. The arm has a cut-out, and a rotating hinge is attached to thelight engine 2560. FIG. 25B illustrates a slightly different positioningfor the hinge. FIG. 25C illustrates another position, in which the hinge2540 is attached to the light engine. In one embodiment, in thisconfiguration, the light engine casing is made out of a solid plastic ormetal material that can support the hinge. In the configuration shown inFIG. 25B, the hinge element 2550 is split, such that support for the armis provided on the top and bottom of the light engine 2560, rather thanhaving a single attachment point.

FIGS. 26A and 26B illustrate embodiments of the hinging element. Thehinging element 2620, 2650 attaches at the top and bottom of the frame.In one embodiment, as shown in FIG. 26A, the arm 2610 may have a cut-outfor the light engine 2630. In one embodiment, the arms may fold forward.These outside hinges in one embodiment are attached on the side of theglasses frame. As can be seen the shape of the hinge element itself maybe varied. FIGS. 26C and 26D illustrate the open and closedconfigurations of an arm 2680, 2690 with an outside hinge 2650, 2670.The arm in one embodiment, has an arm cut-out 2675 for the light engine.

FIGS. 27A-27C illustrate one embodiment of a rotating hinge, in whichthe arm is rotated to open or close. A rotating hinge is configured sothat it is rotated around the axis for opening and closing the arm 2730.The rotating arm 2730 is coupled to the rotating hinge 2720. Therotating hinge is in a first position when it is open, and rotated intothe closed position. Thus, in this configuration there is no bendingelement in the hinge. Rather, the arm is rotated between the twopositions. In one embodiment, a ball joint, universal joint, ball socketor another type of joint is used.

FIG. 28 illustrates one embodiment of a dual hinge. The dual hinge 2830is attached via a hinge connection to the frame 2805 via frameattachment 2840 as well as to the arm, via arm attachment 2845. Thus,the arm 2820 can move, without any impact on the light engine 2850.

FIGS. 29A-29D illustrate one embodiment of glasses with a front rotatingarm, in which the closed position has the arms in front of the lenses.FIG. 29A illustrates the open position, in which the arms are in awearable configuration. FIG. 29B illustrates the closed position, inwhich the arms are positioned in front of the lenses. This isimplemented in one embodiment using a dual hinge 2940 attached to thearm 2930 and to the frame of the glasses. In one embodiment, the hinge2940 provides free movement around the joint, allowing the arm to standout from the glasses, as well as rotate forward. In one embodiment, thehinge 2940 may also permit closure in the conventional configuration.

FIGS. 30A-30B illustrate one embodiment of an over-engine hinge 3020. Aframe attachment element attaches a thin arm 3040 over the light engine3030. Thus, the arm 3040 can move freely between the open and closedpositions, without impacting the light engine 3030.

FIG. 31 illustrates one embodiment of glasses with a foldable bridge. Afoldable bridge 3120 includes a center hinge 3130 which would allow theglasses to be folded shut. In one embodiment, the center hinge 3130 isoffset, such that when folded the two light engines 3140 are offset fromeach other and do not impact each other. This allows storage of theglasses more compactly. In one embodiment, the center hinge 3130 may bea locking hinge that locks into the open position when it is opened.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will, however,be evident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the invention asset forth in the appended claims. The specification and drawings are,accordingly, to be regarded in an illustrative rather than a restrictivesense.

1. A system comprising: optics; an illumination system to direct a lightfrom one or more light sources to the optics; a liquid crystal onsilicon display panel (LCOS) to modulate the light from the optics andto direct the modulated light back to the optics; an in-coupler to acombiner waveguide to receive the modulated light from the LCOS, afterit passes through the optics; such that the illumination light to theLCOS panel and the modulated light from the LCOS panel both pass througha shared subset of the optics.
 2. The system of claim 1, wherein thelight that exits the illumination system and lands on the LCOS fallswithin a volume of the light that forms a limiting output pupil of theoptics.
 3. The system of claim 2, wherein the optics include apolarization filter.
 4. The system of claim 1, wherein the illuminationsystem comprises: one or more LEDs; and an illumination waveguide. 5.The system of claim 4, wherein an out-coupler of the illuminationwaveguide directs the light to the projection optomechanical system; andthe light from the LCOS passes through the illumination waveguide beforeentering the in-coupler of the combiner waveguide.
 6. The system ofclaim 4, wherein the illumination waveguide has an input portion and anoutput portion, and further comprising: a turning coupler in theillumination waveguide between the input portion and the output portion,to enable a change of angles between the input portion and the outputportion.
 7. The system of claim 4, wherein the illumination waveguidecomprises an input portion, an output portion, and a flexible portionbetween the input portion and the output portion.
 8. The system of claim4, wherein the illumination waveguide comprises separate illuminationwaveguides for each color of the light.
 9. The system of claim 8,wherein the combiner waveguide comprises a separate waveguide for eachof the colors of the light.
 10. The system of claim 4, wherein lightfrom an out-coupler of the illumination waveguide passes through aportion of the combiner waveguide before passing through the projectionoptomechanical system.
 11. The system of claim 1, further comprising:the illumination waveguide having a first out-coupler for the lighthaving a first polarization state, and a second out-coupler for thelight having a second polarization state; wherein the projectionoptomechanical system and the LCOS modulate the light having the firstpolarization state for display to a first eye of a user, and furthercomprising: a second projection optomechanical system and a secondcombiner waveguide, for modulating the light having the secondpolarization state for display to a second eye of the user.
 12. Thesystem of claim 1, wherein the projection optomechanical systemcomprises: a polarizing beam splitter; and two mirrors, each of themirrors having an associated quarter-wave plate; such that when thelight enters the projection optomechanical system, the light isreflected from a first mirror, passing through the quarter-wave platetwice, before impacting the LCOS.
 13. The system of claim 1, furthercomprising: a polarizing beam splitter, to split the light after itpasses through the projection optomechanical system; wherein light witha first polarization passes to the LCOS, and light with a secondpolarization is directed to a steerable optics system, the steerableoptics system comprising: steerable optics; a steering element; and asteerable display LCOS; wherein light positioned by the steerable opticssystem returns to the polarizing beam splitter to be combined with thelight with the first polarization, and is in-coupled into the combinerwaveguide.
 14. The system of claim 1, further comprising: anillumination waveguide including a first out-coupler to out-couple lightwith a first polarization, the light with the first polarization to passthrough the projection optomechanical system to the LCOS, and a secondout-coupler to out-couple light with a second polarization, the lightwith the second polarization directed through steerable display opticsand a steerable display LCOS; and the in-coupler of the combinerwaveguide in-coupling light with the first polarization, and thecombiner waveguide including a second in-coupler to in-couple the lightfrom the steerable display LCOS.
 15. The system of claim 1, furthercomprising: an illumination waveguide, the illumination waveguidecomprising a polarization converter to convert unpolarized light in theillumination waveguide to a first polarization.
 16. The system of claim1, wherein the illumination system, the projection optomechanicalsystem, and the LCOS display panel comprise a light engine, and thecombiner waveguide is part of a lens of smart glasses.
 17. The system ofclaim 16, further comprising: hinges on arms of the smart glasses tofold the arms without exerting force on an enclosure protecting thelight engine.
 18. The system of claim 17, further comprising: a firsthinge attached to a lens rim, to provide fitting flexibility, and asecond hinge at which the arms are folded.
 19. A system comprising: anillumination system to direct light from one or more light sources;projection optics; a liquid crystal on silicon display panel (LCOS) toreceive the light from the projection optics, to modulate the light, andto return the modulated light to the projection optics; and anin-coupler to a combiner waveguide to receive the modulated lightthrough the projection optics, the combiner waveguide used to display animage to a user; wherein the light that passes through the projectionoptomechanical system from the illumination system lands on the LCOSwithin the limiting output pupil of the projection optomechanicalsystem.
 20. A near eye display system comprising: a light sourceincluding collimation optics; an illumination waveguide having anin-coupler configured to receive light from the light source, and anout-coupler; an out-bound polarizer positioned in front of theout-coupler of the illumination waveguide; projection optics configuredto receive the light from the out-coupler, through the out-boundpolarizer; a liquid crystal on silicon (LCOS) display configured toreceive the light after it passes through the projection optics, and tomodulate the light, and return the modulated light to the projectionoptics; an in-bound polarizer configured to receive the modulated lightafter it passes through the projection optics; and a combiner waveguideconfigured to receive the modulated light after it passes through thein-bound polarizer, the combiner waveguide configured to display imagedata to a user; wherein the light that passes through the projectionoptics from the illumination waveguide lands on the LCOS within thelimiting output pupil of the projection optics.